The present invention relates to a process for the solubilization of gonococcal antigens, especially those isolated from the cell surface of Neisseria gonorrhoeae. For example, gonococcal lipopolysaccharides, G.sub.c antigens (a family of polysaccharides. See M. A. Apicella et. al, in Immunobiology of Neisseria gonorrhoeae, proceedings of a conference held in San Francisco, Calif., 1978, American Society for Microbiology, Washington, D.C., p. 108), or the antigenic complex as described in U.S. Patent Application Ser. No. 949,581 filed Oct. 12, 1978, now U.S. Pat. No. 4,220,638.
The solubilization of these antigens is essential to their capacity as a vaccine against N. gonorrhoeae for humans. This is because most of these antigens contain water-insoluble determinants such as protein or peptides. In order to inject a vaccine subcutaneously, intravenously or intramuscularly, it is necessary that the antigens which constitute the vaccine be substantially solubilized in a physiologically acceptable medium, for example sterile saline.
The solubilization process of the present invention involves trypsin digestion of the antigen. Although trypsin has been used to digest other bacterial antigens, it has not been used to solubilize gonococcal antigens isolated from N. gonorrhoeae.
Accordingly, it is an object of the present invention to provide a process for solubilization of the gonococcal antigens to be used in a vaccine against N. gonorrhoeae.
Still another object of the present invention is to provide a procedure for solubilizing gonococcal antigens as a means to facilitate the isolation and purification of the active peptides of the antigen in a water-soluble form.